Many afflictions, diseases, and/or general disorders suffered by humans and animals can be successfully treated with light therapy. Some of these light-treatable afflictions relate to biological cells, organisms, tissues residing on and/or within a patient's body. For example, light is known to be effective in the treatment of the skin condition acne vulgaris. Acne vulgaris is due, at least in part, to inflammations caused by infections of propionibacterium acnes (P. acnes). Other applications include the treatment of inflammation, and killing and/or debilitating other bacteria capable of causing infection, such as helicobacter pylori (H. pylori).
H. pylori is a bacterial pathogen that infects the stomach and duodenum, today representing one of the most common gastrointestinal infections in the world. In industrialized nations, such as United States, H. pylori may be found in 20% or more of the adult population. It is a chronic gut infection and, once acquired, is notoriously difficult to eradicate. Although most infectious bacteria can be readily destroyed by the human immune system, H. pylori is relatively resistant to a host immune response, even if vigorous. At least one reason for H. pylori's resistance relates to its residing within the lining of the stomach and on the surfaces of the stomach and duodenal cells.
Effective light therapy, generally, includes an initial pretreatment of the tissue of interest with a photosensitizer. In one example, PhotoDynamic Therapy (PDT) refers to the therapeutic treatment of a portion of a patient's body using light. As an initial step, PDT includes delivering a sensitizing drug to a treatment site of a patient's body. This step is then followed by illumination of the treated area to activate the sensitizing drug.
PDT light sources are typically powered by high-powered sources, such as electrical power source. Light sources include, for example, fluorescent lights, incandescent lights, light emitting diodes, and lasers. Thus, during PDT, a light source, such as an electrical lamp, is shone upon a treatment site for a period of time sufficient to deliver a dosage amount (e.g., a total amount of energy). There are other means for creating light of specific wavelengths. In addition to standard light sources, many exothermic chemical reactions produce at lest some of their energy in the form of photons of specific wavelengths. For example, combustion is one form of chemical reaction that produces photons, the i.e., “flame.” Furthermore, the wavelength of the photons produced are observed in the color of the flames.